Fix inadequate autoconfiscation of copyfile() usage.

Per buildfarm, HAVE_COPYFILE is not the same thing as HAVE_COPYFILE_H.
Add the extra configure test.

configure

@@ -12712,7 +12712,7 @@ $as_echo "#define HAVE_STDBOOL_H 1" >>confdefs.h
 fi
 
 
-for ac_header in atomic.h crypt.h fp_class.h getopt.h ieeefp.h ifaddrs.h langinfo.h mbarrier.h poll.h sys/epoll.h sys/ipc.h sys/prctl.h sys/procctl.h sys/pstat.h sys/resource.h sys/select.h sys/sem.h sys/shm.h sys/sockio.h sys/tas.h sys/un.h termios.h ucred.h utime.h wchar.h wctype.h
+for ac_header in atomic.h copyfile.h crypt.h fp_class.h getopt.h ieeefp.h ifaddrs.h langinfo.h mbarrier.h poll.h sys/epoll.h sys/ipc.h sys/prctl.h sys/procctl.h sys/pstat.h sys/resource.h sys/select.h sys/sem.h sys/shm.h sys/sockio.h sys/tas.h sys/un.h termios.h ucred.h utime.h wchar.h wctype.h
 do :
   as_ac_Header=`$as_echo "ac_cv_header_$ac_header" | $as_tr_sh`
 ac_fn_c_check_header_mongrel "$LINENO" "$ac_header" "$as_ac_Header" "$ac_includes_default"

configure.in

@@ -1295,6 +1295,7 @@ AC_HEADER_STDBOOL
 
 AC_CHECK_HEADERS(m4_normalize([
 	atomic.h
+	copyfile.h
 	crypt.h
 	fp_class.h
 	getopt.h

src/bin/pg_upgrade/file.c

@@ -18,7 +18,7 @@
 
 #include <sys/stat.h>
 #include <fcntl.h>
-#ifdef HAVE_COPYFILE
+#ifdef HAVE_COPYFILE_H
 #include <copyfile.h>
 #endif
 #ifdef __linux__

src/include/pg_config.h.in

@@ -117,6 +117,9 @@
 /* Define to 1 if you have the `copyfile' function. */
 #undef HAVE_COPYFILE
 
+/* Define to 1 if you have the <copyfile.h> header file. */
+#undef HAVE_COPYFILE_H
+
 /* Define to 1 if you have the <crtdefs.h> header file. */
 #undef HAVE_CRTDEFS_H